This invention relates generally to hitching and snatching booms and particularly to a compact boom assembly suitable for mounting to a transporter vehicle.
One of the more common methods of hitching and towing is by drum winches. Hydraulic boom hoists and cranes have also been in use for many years. However, the use of drum winches presents considerable problems. For example, cable life is shortened by the necessity of the cable around the drum. It is very difficult to keep the cable properly wound during operation and yet it must be properly and tightly wound on the drum before retracting the load. Damage to the cable, due to improper winding is not infrequent, and may result in slippage and falls. In addition, it is difficult to inspect a drum wound cable for damage.
U.S. Pat. No. 3,145,857 represents the closest known art, U.S. Pat. Nos. 3,362,550 and 3,667,630 are also representative of the art. In the mobile lift crane and vehicle tow hoist disclosed in U.S. Pat. No. 3,145,857 a vehicle frame is provided having a towing hitch at the front end and a fixed braced post at the rear end. An extensible crane boom is pivoted to the post and is provided with a hook at the front end suitable for lifting engine blocks, and the like, from automobiles straddled by the vehicle frame. In order to hoist disabled vehicles, a towing sling is provided which is slidably mounted to the inclined post brace. The sling is vertically adjusted by a cable which passes over an upper pulley mounted at the top of the post and under a lower pulley mounted below a pivotally attached hydraulic ram which raises and lowers the boom. The lifting and towing systems are essentially seaparate, necessitating a double pulley system.
The present device solves the above problems in a manner not disclosed in the known prior art.